A statute permitting indefinite detention of an alien would raise a serious constitutional problem.
The police said late Tuesday that five more suspects remained in prison under counterterrorism laws permitting detention without charge for 28 days.
The Supreme Court has also permitted "preventive" detention without bail.
Five states have amended their constitutions or passed statutes similar to the 1984 law; 14 others permit preventive detention in limited circumstances.
He also called for better housing for black residents and the elimination of laws permitting detention without trial.
It is possible that the three will never be tried in the case since Salvadoran law permits indefinite detention of suspects.
Something like normal political activities also resumed, albeit under emergency laws permitting prolonged detention.
Initially, he was minded to move to repeal legislation permitting detention without trial.
Suspension of habeas corpus permitted detention, but release usually followed in a few months.
The law permits pre-trial detention of persons accused of serious crimes.